1. Field of the Invention
The present invention relates to a multivalued multiplier which may apply to information processing such as image processing, signal processing in communication, working of fonts for a laser printer, or a microprocessor.
2. Description of the Related Art
In general, the multiplier is a kind of arithmetic and logic operating unit included in a computer and is a circuit dedicated to multiplication. The term "multiplication" herein generally refers to obtaining a partial product of a multiplicand and a part of a multiplier factor (one or more bits) and adding the obtained products.
Recent computers include a built-in multiplying operation as a standard function. Several kinds of methods are applied to the computer for improving the operating performance. Of the methods for enhancing the operating speed of the multiplication, the Booth's method or the Wallis' tree method are well known. The former is arranged to reduce the number of partial products and generating units and simplify each unit, and the latter is arranged to execute additions of partial products in parallel and reduce the adding time.
As another method applying to a very large scaled integration (VLSI), a method has been proposed for arranging basic circuits in a two-dimensional array. A multiplier arranged this method is, in general, well known as an array multiplier.
However, the foregoing multiplying methods for treating only binary signals enable to theoretically yield time allowance but disable to stably execute multiplications at a high speed. This is a disadvantage.
Further, the foregoing serial type or parallel type multiplying method is unable to treat both of a binary signal and a quaternary signal, and is unable to execute multiplications at a high speed. This is also a disadvantage.
In known binary electronics, as the amount of information to be processed is surprisingly increased, the electronic devices and the operating units configuring the hardware are required to be faster and have higher function. The binary electronics technique has a certain limitation in the field of information processing. Moreover, in binary electronics, as the amount of data to be processed becomes larger, it is more difficult to implement the rapid and highly functional electronic devices and operating units.